Work

Elucidating biased signaling in class A GPCRs

Year: 2025

Type: review

Abstract: Biased signaling by G protein-coupled receptors (GPCRs) occurs when ligands selectively activate G proteins or β-arrestins, offering therapeutic potential with fewer side effects. In class A GPCRs, which include the targets of approximately one-third of all marketed drugs, the structural basis of this selectivity remains unclear. Recent cryo-electron microscopy studies, supported by real-time functional assays such as bioluminescence resonance energy transfer and NanoLuc Binary Technology, reveal how distinct ligand binding modes reshape receptor conformations to favor specific transducer engagement. Integrating structural and functional insights enables mapping of isoform- and tissue-specific signaling. Here, we review key mechanisms of bias, including microswitch transitions, intracellular interface remodeling, and allosteric modulation, and provide a mechanistic basis for pathway-selective GPCR-targeting therapeutics with improved efficacy and reduced off-target effects.

Source: Trends in Pharmacological Sciences

DOI: 10.1016/j.tips.2025.10.008

Authors: Ningyang Xu, Edwin Legall, Roger H. Johnson, Lan Zhu, Wei Liu

Institutions: Medical College of Wisconsin, Medical College of Wisconsin Cancer Center

Language: English

Topic: Receptor Mechanisms and Signaling

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $7,030